1. Field of the Invention
This invention relates to liquid sampling catheters such as vascular catheters, specifically in their use to sample volumes of patient liquids, including blood, in clinical settings.
2. Background of the Art
The embodiments described herein relate generally to medical devices. More particularly, the present disclosure relates to a blood sampling device and associated method via a vascular access device. Blood sampling is a common medical procedure involving the withdrawal of at least a drop of blood from a patient. Hospitals, medical clinics, emergency rooms, and health care providers commonly sample liquid from patients either by lancet fingerstick or heel stick devices, venipuncture, or central IV lines. Once collected, blood samples are analyzed via a variety of chemistry tests.
Blood samples are commonly taken to determine the physiological and biochemical state of a patient, and are either analyzed in a laboratory, a distance away from a patient, or at the point of care, near the location of the patient. Clinicians then use this analysis to determine the disease state of a patient, mineral concentrations, organ function, and clinical treatment effectiveness. One example of a common blood test is a point of care blood glucose test, where blood is extracted via a lancet fingerstick, and mechanically transferred onto a testing strip to determine blood glucose values. In other tests, clinicians draw a vial of blood from a venous or arterial source, and then that sample is analyzed in a central laboratory for tens to hundreds of biochemical tests including gas electrolyte levels, protein analysis, and cholesterol quantification, among others.
Despite rapid advancements in both laboratory analysis and point of care testing, current methods of blood sampling have remained relatively unchanged. Each of these methods presents their own unique challenges and issues. Lancets sample capillary blood, which has a higher margin of error in metabolic measurements. These devices also cause discomfort as patients are continually pricked. Venipuncture, the most common method of sampling, when done frequently can cause significant trauma to the venous system and impede the integrity of a patient's veins. Additionally, venipuncture is a manual, labor-intensive process creating significant labor costs by requiring specially trained venipuncture teams within hospitals. It also presents a much higher level of discomfort than lancets. Central line sampling is a more complicated procedure with multiple steps and can be prone to error. Using the same site for infusion and sampling causes an increased chance of sample contamination. Drawing blood from central lines is also known to increase the risk of central line-associated blood stream infections. These blood sampling processes are labor and time intensive, and require multiple devices throughout the sampling process. Furthermore, these methods have many clinical and practical problems associated with their use. Accordingly, there is a need for more efficient and accurate blood sampling devices.
U.S. Pat. No. 8,366,685 (Devgon) describes systems and methods for phlebotomy through a peripheral IV catheter. An actuator is used to advance and retract a sampling cannula that engages a peripheral intravenous line.
US Patent Application (abandoned) Pub. No.: US 2002/0120215 A1, describes a BLOOD COLLECTION SET WITH RETRACTABLE NEEDLE (Crawford) that provides a retractable sheath over a needle sampler, the sheath having horizontal stabilizing wings.